Author: Nathan Sidwell Date: 2023-12-02T11:54:59-05:00 New Revision: 1fa35f0b5dc2f3427fbade0eaaca6e2d8c32caef
URL: https://github.com/llvm/llvm-project/commit/1fa35f0b5dc2f3427fbade0eaaca6e2d8c32caef DIFF: https://github.com/llvm/llvm-project/commit/1fa35f0b5dc2f3427fbade0eaaca6e2d8c32caef.diff LOG: [clang] Avoid recalculating TBAA base type info (#73264) As nullptr is a legitimate value, change the BaseTypeMetadataCache hash lookup/insertion to use find and insert rather than the subscript operator. Also adjust getBaseTypeInfoHelper to do no insertion, but let getBaseTypeInfo do that. Added: Modified: clang/lib/CodeGen/CodeGenTBAA.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CodeGenTBAA.cpp b/clang/lib/CodeGen/CodeGenTBAA.cpp index 8705d3d65f1a5..5906b14dd93cf 100644 --- a/clang/lib/CodeGen/CodeGenTBAA.cpp +++ b/clang/lib/CodeGen/CodeGenTBAA.cpp @@ -342,7 +342,7 @@ llvm::MDNode *CodeGenTBAA::getBaseTypeInfoHelper(const Type *Ty) { // field. Virtual bases are more complex and omitted, but avoid an // incomplete view for NewStructPathTBAA. if (CodeGenOpts.NewStructPathTBAA && CXXRD->getNumVBases() != 0) - return BaseTypeMetadataCache[Ty] = nullptr; + return nullptr; for (const CXXBaseSpecifier &B : CXXRD->bases()) { if (B.isVirtual()) continue; @@ -354,7 +354,7 @@ llvm::MDNode *CodeGenTBAA::getBaseTypeInfoHelper(const Type *Ty) { ? getBaseTypeInfo(BaseQTy) : getTypeInfo(BaseQTy); if (!TypeNode) - return BaseTypeMetadataCache[Ty] = nullptr; + return nullptr; uint64_t Offset = Layout.getBaseClassOffset(BaseRD).getQuantity(); uint64_t Size = Context.getASTRecordLayout(BaseRD).getDataSize().getQuantity(); @@ -378,7 +378,7 @@ llvm::MDNode *CodeGenTBAA::getBaseTypeInfoHelper(const Type *Ty) { llvm::MDNode *TypeNode = isValidBaseType(FieldQTy) ? getBaseTypeInfo(FieldQTy) : getTypeInfo(FieldQTy); if (!TypeNode) - return BaseTypeMetadataCache[Ty] = nullptr; + return nullptr; uint64_t BitOffset = Layout.getFieldOffset(Field->getFieldIndex()); uint64_t Offset = Context.toCharUnitsFromBits(BitOffset).getQuantity(); @@ -418,14 +418,20 @@ llvm::MDNode *CodeGenTBAA::getBaseTypeInfo(QualType QTy) { return nullptr; const Type *Ty = Context.getCanonicalType(QTy).getTypePtr(); - if (llvm::MDNode *N = BaseTypeMetadataCache[Ty]) - return N; - // Note that the following helper call is allowed to add new nodes to the - // cache, which invalidates all its previously obtained iterators. So we - // first generate the node for the type and then add that node to the cache. + // nullptr is a valid value in the cache, so use find rather than [] + auto I = BaseTypeMetadataCache.find(Ty); + if (I != BaseTypeMetadataCache.end()) + return I->second; + + // First calculate the metadata, before recomputing the insertion point, as + // the helper can recursively call us. llvm::MDNode *TypeNode = getBaseTypeInfoHelper(Ty); - return BaseTypeMetadataCache[Ty] = TypeNode; + LLVM_ATTRIBUTE_UNUSED auto inserted = + BaseTypeMetadataCache.insert({Ty, TypeNode}); + assert(inserted.second && "BaseType metadata was already inserted"); + + return TypeNode; } llvm::MDNode *CodeGenTBAA::getAccessTagInfo(TBAAAccessInfo Info) { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
